Heat exchanger support and method of assembling a heat exchanger

ABSTRACT

A heat exchanger that includes a heat exchanger core including a plurality of stacked tubes defining a fluid flow path, a housing substantially surrounding the heat exchanger core, and an elastomeric member positioned between the heat exchanger housing and the heat exchanger core and deformable to allow movement of one of the heat exchanger core and the housing relative to an other of the heat exchanger core and the housing in at least two substantially perpendicular directions.

CROSS-REFERENCE TO RELATED APPLICATION

The present patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/052,299, titled “HEAT EXCHANGER SUPPORT AND METHOD OF ASSEMBLING A HEAT EXCHANGER,” filed on May 12, 2008, the entire contents of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to heat exchangers, and more particularly, to a cantilevered heat exchanger.

SUMMARY

In some embodiments, the invention provides a heat exchanger. The heat exchanger includes a heat exchanger core including a plurality of stacked tubes defining a fluid flow path, a housing substantially surrounding the heat exchanger core, and an elastomeric member positioned between the heat exchanger housing and the heat exchanger core and deformable to allow movement of one of the heat exchanger core and the housing relative to an other of the heat exchanger core and the housing in at least two substantially perpendicular directions.

In other embodiments, the invention provides a cantilevered heat exchanger. The cantilevered heat exchanger includes a housing, a heat exchanger core including a plurality of stacked tubes and extending through the housing, a first end of the core being secured to prevent relative movement between the housing and the core, and an elastomeric member positioned between the housing and the core adjacent a second end of the core.

In yet other embodiments, the invention provides a heat exchanger. The heat exchanger includes a heat exchanger core including a plurality of stacked tubes defining a fluid flow path, a housing substantially surrounding the heat exchanger core, and a protrusion extending outwardly from one of the heat exchanger housing and the heat exchanger core configured to engage a correspondingly shaped recess in the other of the heat exchanger housing and the heat exchanger core to accommodate relative movement in at least two substantially perpendicular directions while supporting an end of the core in the housing.

In other embodiments, the invention provides a method of assembling a heat exchanger. The method includes the acts of positioning a heat exchanger core in a housing, positioning an elastomeric member between a distal end of the core and an interior of the housing, and accommodating movement of the distal end of the core relative to the housing by selectively deforming the elastomeric member between the core and the housing.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a core of a heat exchanger embodying the present invention.

FIG. 2 is an exploded perspective view of the core of the heat exchanger of FIG. 1, a portion of an inlet/outlet manifold, and a housing for the heat exchanger.

FIG. 3 is a sectional view of the core of the heat exchanger of FIG. 1 inside the housing.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

FIGS. 1-3 illustrate a heat exchanger 10 according to some embodiments of the present invention. In some embodiments, including the illustrated embodiments of FIGS. 1-3, the heat exchanger 10 can operate as an exhaust gas recirculation cooler (EGRC) and can be operated with the exhaust system of a vehicle having an internal combustion engine, not shown. In other embodiments, the heat exchanger 10 can be used in other (e.g., non-vehicular) applications, such as, for example, in electronics cooling, industrial equipment, building heating and air-conditioning, and the like. In some applications, for example, the heat exchanger 10 can function as a cooler, a condenser, a radiator, a recuperator, or an evaporator. In addition, it should be appreciated that the heat exchanger 10 of the present invention can take many forms, utilize a wide range of materials, and can be incorporated into various other systems.

During operation and as explained in greater detail below, the heat exchanger 10 can transfer heat from a high temperature first working fluid (e.g., exhaust gas, water, engine coolant, CO₂, an organic refrigerant, R12, R245fa, air, and the like) to a lower temperature second working fluid (e.g., water, engine coolant, CO₂, an organic refrigerant, R12, R245fa, air, and the like). In addition, while reference is made herein to transferring heat between two working fluids, in some embodiments of the present invention, the heat exchanger 10 can operate to transfer heat between three or more fluids. Alternatively or in addition, the heat exchanger 10 can operate as a recuperator and can transfer heat from a high temperature location of a heating circuit to a low temperature location of the same heating circuit. In some such embodiments, the heat exchanger 10 can transfer heat from a working fluid traveling through a first portion of the heat transfer circuit to the same working fluid traveling through a second portion of the heat transfer circuit.

The heat exchanger 10 shown in FIGS. 1-3 includes a heat exchanger core 14 including a number of adjacent and substantially parallel tubes 18, a header 22, a return tank 26, a coolant divider 30, and baffles 34 positioned along the tubes 18. The heat exchanger core 14 can include a first or proximal end 16 and a second or distal end 17. In embodiments in which the heat exchanger core 14 includes a return tank 26, such as the illustrated embodiment of FIGS. 1-3, the return tank 26 can at least partially define the distal end 17 of the heat exchanger core 14. The heat exchanger core 14 or at least a portion of the heat exchanger core 14 can be supported in a housing 38.

As shown in FIGS. 1-3, the heat exchanger 10 defines a first flow path (represented by arrows 20 in FIG. 3) for the first working fluid and a second flow path (represented by arrows 24 in FIG. 1) for a second working fluid, and the first and second flow paths 20, 24 are separated such that the first working fluid is prevented from entering the second flow path 24 and such that the second working fluid is prevented from entering the first flow path 20. More specifically, as shown in FIG. 3, each of the tubes 18 can be secured to the header 22 such that a first working fluid traveling through the heat exchanger 10 enters a first set of tubes (e.g., the three lower tubes 18 in FIG. 3), travels along a first pass through the heat exchanger core 14, passes through the return tank 26, enters a second set of tubes (e.g., the four upper tubes 18 of FIG. 3), travels along a second pass through the heat exchanger core 14, and is maintained separate from a second working fluid traveling through the heat exchanger 10.

The second working fluid enters the interior space defined between the inner wall of the housing 38 and the heat exchanger core 14 and travels along the second flow path 24 before exiting the heat exchanger 10 through an outlet (not shown). In the illustrated embodiment of FIGS. 1-3, the second flow path 24 extends across the exterior surfaces of the tubes 18 and serpentines around the coolant divider 30 and baffles 34 such that heat can be transferred between the first fluid traveling along the first flow path 20 through the heat exchanger core 14 and the second fluid traveling along the second flow path 24 through the heat exchanger housing 38.

In some embodiments, the tubes 18 can be formed from aluminum, steel, iron, or other metal, whereas the header 22 can be plastic. Although this material combination provides unique performance results, other materials and material combinations are possible. For example, in other embodiments, both the core 14 and the header 22 are formed from plastic. In other embodiments, both the core 14 and the header 22 are formed from metal. Alternatively, in still other embodiments, the core 14 is plastic, while the header 22 is formed from one or more metals. In the illustrated embodiment, the return tank 26 is metal. Alternatively, in still other embodiments, the return tank 26 or a portion of the return tank 26 can be plastic.

As shown in FIGS. 1-3, the core 14 can be supported in a housing 38 in a cantilevered manner such that the distal end 17 of the core 14 is moveable relative to the housing 38. The housing 38 can be formed from cast aluminum or steel, formed sheet metal, plastic, or similar housing material. Alternatively, the housing 38 or a portion of the housing 38 can be formed from a material having a greater elasticity, such as, for example, plastic. The housing 38 is shown in FIGS. 2 and 3 as having a smooth outer surface and configured to couple to an exterior portion of the inlet/outlet manifold 12. However, in other embodiments, the housing 38 may have bumps, ridges, or other protrusions creating a non-smooth outer surface.

As shown in FIG. 2, the header 22 can be secured to an inlet/outlet manifold 12, and a seal can be formed between the header 22, an exterior portion of the inlet/outlet manifold 12, and the housing 38. In this manner, the proximal end 16 of the core 14 is prevented from moving relative to the housing 38 and/or relative to the header 22.

The coolant divider 30 extends axially along the length of the core 14 between the proximal and distal ends 16, 17 of the core 14 and is configured, among other things, to separate the heat exchange tubes 18 so as to define first and second passes through the core 14. For example, in the illustrated embodiment of FIG. 3, the divider 30 defines a first pass through the core 14 along the three lower tubes 18 and a second pass through the core 14 along the four upper tubes 18. As shown in FIGS. 1 and 2, comb-shaped baffles 34 are positioned on opposite sides of the core 14 along the length of the core 14 to define a serpentine flow path between the exterior of the core 14 and the interior of the housing 38. The baffles 34 can also or alternatively support the tubes 18 in the housing 14 and maintain a desired relative spacing between the tubes 18.

In some embodiments, the coolant divider 30 and/or the baffles 34 can extend outwardly from the core 14 and contact the interior of the housing 38. In some such embodiments, the coolant divider 30 and/or the baffles 34 can support the distal end 17 of the core 14 within the housing 38, while accommodating thermal expansion of the core 14 relative to the housing 38 and/or absorbing vibrations. In some such embodiments, the coolant divider 30 and/or the baffles 34 can also accommodate axial movement of the core 14 (i.e., in a direction substantially parallel to the axis A shown in FIG. 1). Alternatively or in addition, the coolant divider 30 and/or the baffles 34 can also accommodate movement of the core 14 relative to the housing 38 in a direction substantially perpendicular to the axis A. In still other embodiments, the coolant divider 30 and/or the baffles 34 can also accommodate pivoting movement of the core 14 relative to the housing 38 when one side (e.g., the upper side) of the core 14 experiences different thermal expansion than the opposite side (e.g., the lower side) of the core 14, causing the core 14 to bend or twist relative to the housing 14. The movement of the core relative to the housing can be along any direction, a plane, and/or an arc. In embodiments in which the housing moves relative to the core, movement can be along any direction, a plane, and/or an arc.

In some embodiments in which the coolant divider 30 and/or the baffles 34 support the core 14 within the housing 38, the outer ends of the coolant divider 30 and/or the baffles 34 can extend outwardly and engage the inner wall of the housing 38. In some such embodiments, the exterior edges of the coolant divider 30 and/or the baffles 34 can be at least partially covered with an elastomeric material (e.g., rubber, plastic, etc.) to accommodate the movement of the core 14 relative to the housing 38 and/or to absorb vibrations.

In other embodiments, the exterior edges of the coolant divider 30 and/or the baffles 34 can be curved over and can ride along the interior surface of the housing 38. In this manner, the exterior edges of the coolant divider 30 and/or the baffles 34 can be compressed or expand to accommodate movement of the core 14 relative to the housing 38. In this manner, the elasticity provided by the curved exterior edges can function as a spring. Also, the exterior edges of the coolant divider 30 and/or the baffles 34 can move across the inner wall of the housing 38 in a wiping manner to prevent fluid from traveling between the inner wall of the housing 38 and the outer edges of the coolant divider 30 and/or the baffles 34, even when thermal expansion causes the core 14 to move more closely to or further from portions of the inner wall of the housing 38.

In other embodiments, an elastomeric material may be secured to the exterior edges of the coolant divider 30 and/or the baffles 34 and the exterior edges of the coolant divider 30 and/or the baffles 34 can be seated or at least partially seated in grooves formed along the inner wall of the housing 38 to accommodate longitudinal expansion of the heat exchanger core 14.

As shown in FIGS. 1 and 3, the return tank 26 can include an outwardly extending protrusion 42. The protrusion 42 can be any shape or size that protrudes, or otherwise extends outwardly from the exterior of the return tank 26. In the illustrated embodiment of FIGS. 1-3, the protrusion 42 is formed into the return tank 26. In other embodiments, the protrusion 42 may be welded, soldered, or brazed onto the return tank 26.

In the illustrated embodiment of FIGS. 1 and 3, the protrusion 42 extends outwardly from one end of the return tank 26. In other embodiments, the protrusion 42 can be positioned in other locations along the exterior of the return tank 26, such as, for example, on an upper surface, a lower surface, the right side, or left side of the return tank 26. In still other embodiments, two or more protrusions 42 can extend outwardly from the same or different sides or surfaces of the return tank 26. In some such embodiments, one protrusion 42 can be located on a first surface (e.g., the left side) of the return tank 26 and another protrusion 42 can be located on an opposite surface (e.g., the right side) of the return tank 26.

In the illustrated embodiment of FIGS. 1-3, the protrusion 42 is configured to be received or at least partially received in a recess 50 formed in the inner wall of the housing 38. In other embodiments, the protrusion 42 can be received or at least partially received in a recess formed in an element (e.g., a liner, a fastener extending into the housing 38, etc.) secured to the inner wall of the housing 38.

As shown in FIG. 3, an elastomeric member 46 is supported in the recess 50 and is configured to matingly receive the protrusion 42 so as to support the protrusion 42 and the distal end 17 of the heat exchanger core 14. In the illustrated embodiment, the elastomeric member 46 is a grommet formed from plastic, rubber, or a similar resilient and deformable material. However, in other embodiments, the elastomeric member 46 can be formed from a metal or other rigid material and can be shaped to act as a spring.

The elastomeric member 46 is deformable to allow movement of the heat exchanger core 14 relative to the housing 38 and to accommodate vibrations and/or thermal expansion in at least two substantially perpendicular directions, and in some embodiments, in three substantially perpendicular directions. Also, in some embodiments, the durometer of the elastomeric member 46 is sufficiently high so that the engagement between the elastomeric member 46 and the protrusion 42 supports the distal end 17 of the heat exchanger core 14 while also allowing for limited movement of the heat exchanger core 14 with respect to the housing 38.

In other embodiments, the return tank 26 may have two, three, or more protrusions 42 configured to sit in a recess or a plurality of recesses 50 formed on the inner wall of the housing 38 or on an element supported on the inner wall of the housing 38. In some such embodiments, elastomeric members 46 having different durometers can be supported in each of the recesses 50. In other embodiments, each of the recesses 50 can support an elastomeric member 46 and all of the elastomeric members 46 can have the same durometer.

In still other embodiments, a reverse design may be employed wherein the protrusion 42 extends inwardly from the inner wall of the housing 38 and is further configured to be received in an opening in an elastomeric member 46 supported in a recess 50 formed in the return tank 26. In other embodiments, protrusions 42 may extend from both the return tank 26 and the housing 38 and a washer, sleeve, bushing, or similar elastomeric member 46 may provide interference between the protrusions 42. In some such embodiments, both protrusions 42 can be formed from or covered with an elastomeric material. In other embodiments, the insert positioned between the protrusions 42 can also or alternatively be formed from or covered with an elastomeric material to accommodate relative movement between the protrusions 42 and/or to absorb vibrations.

In yet other embodiments, the return tank 26 and the housing 38 may be substantially planar and a washer, gasket, or similar elastomeric member 46 may provide an interference between the return tank 26 and the housing 38. In some such embodiments, the elastomeric member 46 can be positioned around or at least partially around the exterior surface of the return tank 26. Alternatively or in addition, the elastomeric member 46 can be at least partially received in a recess 50 formed around the external surface of the return tank 26 and/or the internal wall of the housing 38 to maintain the elastomeric member 46 in a desired position while also absorbing vibrations and/or allowing relative movement between the return tank 26 and the housing 38.

In still other embodiments, the return tank 26 can be formed with a stamped bead pattern configured, among other things, to help direct fluid (e.g., exhaust) flow along the first flow path 20 through the return tank 26 and seat a washer, gasket, or similar elastomeric member 46 on an exterior surface of the return tank 26 between the exterior surface of the return tank 26 and the inner wall of the housing 38. Alternatively, in other embodiments, an interference fit can be maintained between the heat exchanger core 14 and the housing 38 in addition to or without any elastomeric member 46 between the heat exchanger core 14 and the housing 38.

In alternate embodiments, a fastener, such as, for example, a screw, nail, rivet, pin, post, clip, clamp, inter-engaging element, and any combination of such fasteners, can be inserted through the housing 38 to press or otherwise interface with the return tank 26 and provide support to the heat exchanger core 14. In some embodiments, the fastener may include an elastomeric exterior or be at least partially covered with an elastomeric material.

In still other embodiments, a fastener or a hollow protrusion can extend outwardly from the return tank 26 toward the inner wall of the housing 38, or alternatively, a fastener or a hollow protrusion 42 can extend inwardly from the inner wall of the housing 38 toward the return tank 26. In some such embodiments, an opening provided in the fastener or the hollow protrusion 42 can provide an alternate exit or bypass for fluid exiting the heat exchanger core 14. In some such embodiments, the opening provided in the fastener or the hollow protrusion 42, which can extend from either the return tank 26 or the housing 38, can be substantially aligned with an opening on either the return tank 26 or the housing 38 and a hollow elastomeric member 46 can be positioned between the opening and the fastener or hollow protrusion 42 so as to provide an alternate exit or bypass for fluid exiting the heat exchanger core 14. In some such embodiments, a valve can be provided to control flow through such an alternate exit or bypass. Such an alternate exit or bypass can also or alternatively function as a condensation trap, while the fastener or hollow protrusion 42 can be formed of or at least partially covered with an elastomeric material, as described above, to accommodate relative movement between the heat exchanger core 14 and the housing 38.

While reference is made herein to protrusions 42 located along the return tank 26 to be received in recesses 50 formed along the inner wall of the housing 38 and to recesses 50 formed along the return tank 26 to receive protrusions 42 extending inwardly from the housing 38, in some embodiments of the present invention, protrusions 42 can also or alternatively extend outwardly from other locations along the heat exchanger core 14, such as, for example, from the tubes 18, to be received in recesses 50 located along the inner wall of the housing 38. Alternatively or in addition, protrusions 42 can extend inwardly from the inner wall of the housing 38 to be received in recesses 50 formed along other portions of the heat exchanger core 14, such as, for example, the tubes 18. Similarly, fasteners such as, for example, screws, nails, rivets, pins, posts, clips, clamps, inter-engaging elements, and any combination of such fasteners, can be inserted through the housing 38 to press or otherwise interface with the other portions of the heat exchanger core 14, such as, for example, the tubes 18. Also or alternatively, grommets, bushings, washers, or other elastomeric members 46 can be positioned between other portions of the heat exchanger core 14 and the inner wall of the housing 38 to accommodate relative movement and/or to absorb or at least partially absorb vibrations.

In some such embodiments, the heat exchanger core 14 can be formed without a return tank 26. In these embodiments, each of the tubes 18 of the heat exchanger core 14 can be formed to have a substantially U-shape such that the fluid traveling through the first flow path 20 travels through the heat exchanger core 14 along at least two passes. In some such embodiments, a header 22 can be secured to the distal end 17 of the heat exchanger core 14 and the header 22 can engage one or more elastomeric members 46 positioned along the inner wall of the housing 38 to support or at least partially support the distal end 17 of the heat exchanger core 14 while also accommodating relative movement between the heat exchanger core 14 and the housing 38 and/or absorbing vibrations.

The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention. Variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described. Various features and advantages of the invention are set forth in the following claims. 

1. A heat exchanger comprising: a heat exchanger core including a plurality of stacked tubes defining a fluid flow path; a housing substantially surrounding the heat exchanger core; and an elastomeric member positioned between the heat exchanger housing and the heat exchanger core and deformable to allow movement of one of the heat exchanger core and the housing relative to an other of the heat exchanger core and the housing in at least two substantially perpendicular directions.
 2. The heat exchanger of claim 1 wherein the core includes a return tank connecting sections of adjacent tubes to define a substantially U-shaped portion of the flow path.
 3. The heat exchanger of claim 2 wherein the elastomeric member is positioned on the return tank.
 4. The heat exchanger of claim 2 wherein the return tank is located at a distal end of the core.
 5. The heat exchanger of claim 2 wherein one of the housing and the return tank includes an outwardly extending protrusion and an other of the housing and the return tank defines a recess configured to receive the protrusion.
 6. The heat exchanger of claim 5 wherein the elastomeric member is positioned in the recess and is engageable with the protrusion.
 7. The heat exchanger of claim 1 wherein the elastomeric member extends outwardly from the housing.
 8. The heat exchanger of claim 1 wherein the heat exchanger is an exhaust gas recirculation cooler.
 9. The heat exchanger of claim 1 wherein the one of the heat exchanger core and the housing is moveable in a third direction substantially perpendicular to each of the at least two directions.
 10. The heat exchanger of claim 1 wherein the movement of the one of the heat exchanger core and the housing in one of the two directions is along an arc.
 11. A cantilevered heat exchanger comprising: a housing; a heat exchanger core including a plurality of stacked tubes and extending through the housing, a first end of the core being secured to prevent relative movement between the housing and the core; and an elastomeric member positioned between the housing and the core adjacent a second end of the core.
 12. The cantilevered heat exchanger of claim 11 wherein the second end of the heat exchanger core is moveable in a first direction substantially parallel to a length of at least one tube of the plurality of stacked tubes relative to the housing and in a second direction substantially perpendicular to the first direction to accommodate at least one of thermal expansion of the core and vibrations.
 13. The cantilevered heat exchanger of claim 11 wherein the elastomeric member extends outwardly from one of the heat exchanger housing and the heat exchanger core and engages a correspondingly shaped recess in an other of the heat exchanger housing and the heat exchanger core to accommodate relative movement while supporting the second end of the core in the housing.
 14. The cantilevered heat exchanger of claim 11 wherein the elastomeric material at least partially surrounds a protrusion extending outwardly from the one of the heat exchanger housing and the heat exchanger core and engageable in a correspondingly shaped recess in the other of the heat exchanger housing and the heat exchanger core to accommodate relative movement while supporting the second end of the core in the housing.
 15. The cantilevered heat exchanger of claim 11 wherein the core includes a return tank connecting sections of adjacent tubes to define a substantially U-shaped portion of the flow path.
 16. The cantilevered heat exchanger of claim 15 wherein the elastomeric member is positioned on the return tank.
 17. The cantilevered heat exchanger of claim 11 wherein the heat exchanger is an exhaust gas recirculation cooler.
 18. The cantilevered heat exchanger of claim 12 wherein the one of the heat exchanger core and the housing is moveable in a third direction substantially perpendicular to each of the at least two directions.
 19. A heat exchanger comprising: a heat exchanger core including a plurality of stacked tubes defining a fluid flow path; a housing substantially surrounding the heat exchanger core; and a protrusion extending outwardly from one of the heat exchanger housing and the heat exchanger core configured to engage a correspondingly shaped recess in the other of the heat exchanger housing and the heat exchanger core to accommodate relative movement in at least two substantially perpendicular directions while supporting an end of the core in the housing.
 20. The heat exchanger of claim 19 wherein the core includes a return tank connecting sections of adjacent tubes to define a substantially U-shaped portion of the flow path.
 21. The heat exchanger of claim 20 wherein the return tank is located at the end of the core.
 22. The heat exchanger of claim 19 wherein the heat exchanger is an exhaust gas recirculation cooler.
 23. The heat exchanger of claim 19 wherein the one of the heat exchanger core and the housing is moveable in a third direction substantially perpendicular to each of the at least two directions.
 24. The heat exchanger of claim 19, further comprising an elastomeric member positioned between the protrusion and the recess.
 25. The heat exchanger of claim 19 wherein the protrusion is at least partially formed of an elastomeric material.
 26. The heat exchanger of claim 19 wherein the movement of the one of the heat exchanger core and the housing in one of the two directions is along an arc.
 27. A method of assembling a heat exchanger, the method including the acts of: positioning a heat exchanger core in a housing; positioning an elastomeric member between a distal end of the core and an interior of the housing; and accommodating movement of the distal end of the core relative to the housing by selectively deforming the elastomeric member between the core and the housing.
 28. The method of claim 27 wherein the elastomeric member substantially surrounds a protrusion extending outwardly from one of the heat exchanger housing and the heat exchanger core.
 29. The method of claim 27 wherein the elastomeric member is deformable to allow movement of one of the heat exchanger core and the housing relative to an other of the heat exchanger core and the housing in at least two substantially perpendicular directions.
 30. The method of claim 29 wherein the one of the heat exchanger core and the housing is moveable in a third direction substantially perpendicular to each of the at least two directions.
 31. The method of claim 27 wherein the elastomeric member is deformable to allow movement of one of the heat exchanger core and the housing relative to an other of the heat exchanger core in a first direction and in a second direction along an arc. 